The present invention relates generally to communication systems and in particular, to blind transport format detection within such communication systems.
During communication, a mobile unit may be transmitting several differing data streams (transport channels) over a single over-the-air channel. For example, control and application data may be multiplexed onto a single over-the-air channel transmitted to infrastructure equipment. Each data stream may be capable of being transmitted in several formats. For example, each data stream has its own bit rate, channel coding type, block size, transmission time interval (TTI). . . . , etc.
FIG. 1 illustrates the multiplexing of two data streams. Although each data stream may in actuality be capable of transmitting in many differing transport formats (TFs), for simplicity data streams 1 and 2 are shown having only two transport formats. As shown data stream 1 is capable of transmitting at 0 or 9.6 Kbps, while data stream 2 is capable of transmitting at 0 or 300 Kbps. That is, data stream 1 has two differing TFs, with TF11=0 Kbps and TF12=9.6 Kbps, while data stream 2 also has two differing transport formats with TF21=0 Kbps and TF22=300 Kbps.
At any given time, each data stream may be transmitting any of their various transport formats. For example, a transport format combination (TFC) of TF11=0 Kbps, and TF22=300 Kbps may be entering multiplexer 101. As illustrated in FIG. 1, there exists four transport format combinations, with TFC1={TF11, TF21}, TFC2={TF11, TF22}, TFC3={TF12, TF21}, and TFC4={TF12, TF22}. In general, if there exists I transport channels each of which has Ji transport formats, there exists       ∏          i      =      1        I    ⁢      J    i  
possible transport format combinations.
During blind transport format detection, a receiver has no indication which of the   K  =            ∏              i        =        1            I        ⁢          J      i      
possible transport format combinations is being utilized by the transmitter. Prior-art solutions to the problem have dealt with determining the transport format of a single channel only. For example, section A.1.2 of the 3rd Generation Partnership Project (3GPPP) TS 25.212 v3.5.0 describes a blind transport format detection of a single data channel using a cyclic-redundancy check (CRC). Such prior-art methods fail to describe the determination of a transport format where multiple data channels are multiplexed onto a single over-the-air channel. Therefore, a need exists for a blind transport format detection for a received signal that efficiently determines what transport format combination is currently being utilized by a transmitter multiplexing several transport channels onto a single over-the-air channel.